Deepwater Horizon’s Impacts Found in Bacteria

Nobody’s going to shed a tear for an oiled microbe, but the Deepwater Horizon’s impacts include bacteria, underscoring just how subtle and fundamental the blowout’s ecological consequences may be.

The findings, based on comparisons of microbial flux before and after oil washed ashore, are not a final analysis. It’s too soon to say how long-lasting those fluctuations were, or what they meant to other creatures. Instead they’re a starting point, an early observation in research that will continue for years, even decades.

“While visible damages are evident in the wildlife populations and marine estuaries, the most significant effect may be on the most basic level of the ecosystems: the bacterial and plankton populations,” wrote researchers in a study Feb. 28 in Nature Precedings. “Abrupt and severe changes in the microbial metabolism can produce long-term effects on the entire ecosystem.”

Led by biologist William Widger of the University of Houston, the researchers sequenced DNA from near-shore water and beach-soil samples gathered before and after oil arrived in Gulfport, Mississippi, and Grand Isle, Louisiana, following the blowout last spring.

By cross-referencing the DNA to microbe gene databases, they identified populations of bacteria and how they changed. Vibrio cholera, the bug that causes cholera, spiked upward after the spill. So did Rickettsiales, an order of bugs whose diseases include typhus and spotted fever.